Poultry industry in Egypt was subjected to various problems one of them was the early chick mortalities that cause great economic losses and its investigation is the request of many poultry scientists and men. In poultry staphylococci, including Staphylococcus aureus are known to cause various diseases from acute septicemia to chronic osteomyelitis. Two hundred and sixty samples of chickens, ducks and turkeys were collected from different poultry farms. A survey on Staphylococcal infection among chickens, ducks and turkeys was carried out. It was found that out of 260 infected and dead chickens, ducks and turkeys suspected to be infected with Staphylococcosis, 54 cases (20.76%) revealed Staphylococcus micro-organisms. The isolated strains were typed as: Staphylococcus aureus (74.07%), Staphylococcus epidermidis (14.8 %)and Staphylococcus saprophyticus (11%). The results of sensitivity biogram revealed that S. aureus were highly sensitive to Amoxicillin, Ampicillin, Ciprofloxacine, Enrofloxacine and lincomycin and resistant to Erythromycin, Streptomycine and Chloramphenicol. The results of MIC of 6 representative coagulase positive Staphylococci isolates against 6 selected antibiotics commonly used in poultry farms showed that 100% of isolates were sensitive to amoxicillin, enrofloxacin, ciprofloxacin and oxytetracyclin, while 100% of 6 isolates were resistant to streptomycin and lincomycin. The incidence of isolation of Staphylococci from the internal organs of examined birds and from unabsorbed yolk sac, joints, liver, intestinal content and heart blood was 36.3%, 20%, 19.2%, 17.3% and 16.9% respectively. Ten of each detected isolates were examined by cPCR for resistance genes blaZ and aac(6') aph (2''). The isolates harbored these resistance genes with percentage of 100% for S. aureus. In experiment, the pathogenicity of the isolated strains of S. aureus for 7 day- old chicks was studied. S. aureus injected subcutaneously, oral and intranasal caused death of 100%, 100% and 26.7% of the used chicks respectively.